A fundamental concept of telecommunications involves transferring information, which may, for example, be voice, video, and/or data, between two endpoints through a telecommunication network. A telecommunication network includes links (or communication channels), and nodes, which are the points of interconnection for the links within the network. Generally, a typical telecommunications network includes core networks and edge networks. A core network includes devices that communicate information at high speeds between different edge networks. An edge network, which resides at a border of the telecommunications network, connects the end user to the core network.
A typical edge network includes central offices linked to each other via interoffice links. A central office may function as an end office or a tandem office depending on the central office's location in the edge network. An end office is a connection point within the edge network between at least one tandem office and end users. A tandem office is a connection point within the edge network between at least one end office and at least one point of presence (POP) switch. An end office includes edge devices, such as local switches, which connect end users to tandem offices. A tandem office includes a tandem switch. A tandem switch connects at least one end office to at least one point of presence (POP) switch. A POP switch is an information gateway between at least one end office (via a tandem switch) and at least one core network. A tandem switch is capable of transmitting and receiving information from network services that conform to a variety of protocols, such as asynchronous transfer mode (ATM), time division multiplexing (TDM), frame relay (FR), and internet protocol/multiprotocol label switching (IP/MPLS), for example.